特高压直流故障的快速精细化静态安全分析

Fast and refined static security analysis of UHVDC fault

特高压直流相关的单回或多回直流闭锁故障可能存在严重静态安全问题,需要进行在线分析计算。目前采用动态潮流方法难以快速准确模拟故障后安控装置动作,文中按照安控先动作、发电机一次调频随后动作的时序,通过估算最低频率采用准静态方法模拟安控装置动作,进而计及一次调频特性获得预想故障下节点有功注入变化;针对直流控保无功电压控制模拟结果不准确问题,在计算中考虑换流站交流母线节点类型的转换逻辑,避免节点类型转换振荡,同时分析了无功电压控制模拟对潮流收敛性的改进,并通过某实际电网的算例验证了方法的有效性。

There may be serious static security problem after UHVDC related single or multiple DC locking faults,on-line analysis is necessary.At present,on-line simulation computational speed of the security&stability control is difficult to meet analysis requirements and the results of DC reactive power control strategies are not accurate.An On-line static security analysis method of UHVDC faults is proposed,considering the security&stability control strategies and primary frequency regulation characteristics.A quasi-static simulation method is used to estimate the change of active injection of each node under the faults,according to time sequence of security&stability control first action and primary frequency regulation second action.In the simulation,the DC reactive power control function model is established by the bus type conversion of the converter station,thus the accuracy and convergence of the calculation is improved.The effectiveness of proposed method is verified by actual cases.